Telemark skiing is often thought of as a cross between downhill skiing and cross-country skiing. Like cross-country skiing, the heel of a telemark boot is not secured to the ski, i.e., it is a "heel-less" binding. However, the toe piece of a telemark binding generally provides a more secure attachment of the toe of the boot to the ski than does a cross-country ski binding. Also, the ski boots for telemark skiing are generally heavier than those used for cross-country skiing. Consequently, a telemark ski, boot, and binding outfit generally provides superior control over a cross-country outfit, albeit not to the same degree as does an alpine (commonly referred to as "downhill") ski, boot, and binding assembly.
One problem associated with telemark ski bindings is that the mounting screws that secure the toe piece to the ski tend to work loose over time. If the mounting screws are not kept securely tightened, the holes in the ski will tend to become enlarged, preventing further tightening of the binding mounting screws. Worse yet, the holes may fail during actual skiing, causing the binding to detach from the ski. Besides being a significant inconvenience, the detaching binding may cause personal injury to the skier.
In an effort to ameliorate this problem, some skiers install threaded inserts into their skis. The mounting screws of the binding are then secured to the threaded inserts. While such threaded inserts provide a more secure attachment of binding to ski, the binding may still pull loose from the ski when subjected to heavy loads of the type that may be imposed by an accidental fall or by expert or "extreme" telemark skiers.